Articulated beds or bed frames for the home market have not heretofore achieved significant commercial success and such beds have been marketed for the most part as a hospital or nursing home product and with such objectives have been over designed and overly complicated and as a result have been too costly for the residential or home market for articulated beds.
Over the last several decades articulated chairs and sofas have achieved some commercial success in the residential market but only recently has such technology been adapted for the residential articulated bed marketplace.
A primary consideration in the design of articulated beds and components therefore in the residential market is ease of shipment because a container the size of an entire complete articulated bed assembly would not only be excessively large but too heavy for a single delivery person to bring into the home to install.
One attempt at solving this problem is illustrated in the Elliott U.S. Pat. No. 4,381,571 which shows an articulated mattress spring that is adapted to fit on top of and rest on a separate simple rectangular bed frame. The Elliott power drive module or mattress frame includes large stationary "L" shaped side sections with cross members to provide support for axial oriented motor and screw assemblies that drive complicated four bar linkages at the four corners of the module that serve to raise and lower the head and leg sections of the mattress support. While Elliott suggests that these parts, numbering literally hundreds, may be disassembled for shipment it is realistically not practical to have the purchaser reassemble this complex device in his or her home.
A similar articulated bed is illustrated in the Neumann U.S. Pat. No. 4,120,057 and it shows a power system for an articulated mattress support and, like the Elliott design, is adapted to fit into a bed frame. The problem with the Neumann device is that it requires a large rectangular frame the size of the bed frame itself so that no size reduction is practically possible in the Neumann system.
Furthermore in the Elliott device the power module with drive motors, gearing and rocker shafts, requires that the rocker shafts be mounted in outboard bearings, i.e. bearings in the large rectangular frame described above and such outboard bearings denigrate the capability of shipping the power module in easily carried containers without requiring any significant reassembly at the purchaser's location.
Other articulated beds are illustrated in the Muir U.S. Pat. No. 1,397,773 and the Szemplak, et al. U.S. Pat. No. 3,051,965. The patent to Muir also shows a device for adjusting the articulated bed. Double motor-type systems are shown in the Taylor U.S. Pat. No. 2,500,742. Another standard articulated bed frame is illustrated in Hanning, et al. U.S. Pat. No. 3,921,230.
It is the primary object of the present invention to provide a power module for an articulate bed assembly that ameliorates the problems noted above in prior articulated bed designs.